JP7337116B2 - Power supply system and method - Google Patents

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to US Provisional Patent Application No. 63/009,176, filed April 13, 2020, the disclosure of which is hereby incorporated by reference in its entirety.

The described subject matter relates to systems and methods for delivering current to a powered system for powering the powered system. technical discussion

Some powered systems are supplied with current from a remote location by a conductive path. For example, some vehicles may have pantographs that contact overhead lines that supply direct current (DC) to the vehicles via cables and pantographs. One type of these vehicles are mining vehicles, such as tow trucks, that operate in underground mines and above-ground open pit alpine. Power plants (eg, power plants) can generate alternating current (AC) that is stepped up to relatively large voltages by one or more stationary transformers. This generated AC can be boosted from 138 kV to 100 kV or higher, such as 765 kV, and have a frequency of 50 or 60 hertz (Hz). This high voltage, low frequency AC can be conducted via catenary lines to one or more off-board transformer substations within the mine, where the high voltage, low frequency AC is It is stepped down to a reduced voltage and/or increased frequency for transmission within the mine. As an example, this reduced voltage for power transmission in mines may be 11 kV or less, and the AC increased frequency may be 50-60 Hz. These transformer substations are roadside transformers in that the transformers are all outside the vehicle and do not move with the vehicle.

Reduced voltage, increased frequency AC is directed through a transmission line from a stationary roadside transformer substation to one or more off-board rectifiers. These rectifiers are roadside rectifiers that are not installed on any vehicle. For example, the rectifier is stationary and does not move with the vehicle. The rectifier converts the increased frequency AC at reduced voltage to DC, such as 1.8 kV to 2.4 kV DC which is led to the pantograph of the vehicle via the transmission line. The vehicle receives DC from the power line and powers the vehicle's electric traction motors to propel the vehicle.

One problem with this type of power supply system is the off-vehicle, stationary, roadside step-down transformer that regulates and changes the AC directed along the transmission line to a DC waveform that can be used by the vehicle. and an off-vehicle, stationary, roadside rectifier. AC currently routed along power lines cannot be used in at least some known mining vehicles. In addition, AC that is routed through power lines can limit what electronic components can be coupled between the vehicle's motor and the power lines. Since the frequency and peak voltage of line-guided AC is fixed (e.g., controlled by an external source such as a power plant), any electronic component that can receive AC from the line must be a specific electronic component. is limited to The electronics that receive the AC and modify it for use by the motor may generally not be able to simply switch to other electronics due to the fixed frequency and peak voltage of the AC provided by the external source. unknown. It would be desirable to have systems and methods that differ from those currently available.

In one embodiment, the power supply system includes an on-board rectifier configured to be located on-board a vehicle. The on-board rectifier may be configured to receive alternating current directed from the power plant over the transmission line at a frequency that is at least the utility line frequency. The on-board rectifier may change the alternating current to direct current and output the direct current to the vehicle's electrical propulsion system to power the propulsion system and propel the vehicle.

In one embodiment, a method is provided that includes receiving alternating current at an on-board rectifier located on-board an electric vehicle. Alternating current is received by the on-board rectifier from the power plant over the transmission line and at a frequency that is at least the utility line frequency. The method also includes converting the alternating current to direct current using an on-board rectifier and supplying the direct current from the on-board rectifier to an electrical propulsion system of the vehicle, thereby powering the propulsion system. and propelling the vehicle.

In one embodiment, the method comprises receiving alternating current at a frequency of at least 50 Hz from a power plant on an electric vehicle via one or more transmission lines; rectifying the alternating current to direct current on the electric vehicle; powering a propulsion system of the vehicle using direct current to power the propulsion system to propel the electric vehicle.

In one embodiment, a method is provided comprising the steps of conducting alternating current from a power plant at utility power line frequency through one or more transmission lines; is not rectified off-board between the power plant and the vehicle; rectifying the alternating current on-board the vehicle to thereby generate a direct current; and and C. powering the electric traction motor.

The inventive subject matter can be understood from reading the following description of non-limiting embodiments, with reference to the accompanying drawings.
1 shows an example of a power supply. 4 shows another example of a power supply. 4 shows another example of a power supply. 4 shows another example of a power supply. 4 shows another example of a power supply. 1 shows a flowchart of one embodiment of a method for powering a motor of a vehicle and powering a motor. FIG. 4 illustrates a flow chart of an embodiment of another method for powering a motor of a vehicle and powering the motor; FIG. FIG. 4 illustrates a flow chart of an embodiment of another method for powering a motor of a vehicle and powering the motor; FIG. FIG. 4 illustrates a flow chart of an embodiment of another method for powering a motor of a vehicle and powering the motor; FIG. 1 is a schematic diagram showing an embodiment of an on-board rectifier; FIG. 3 shows another example of the power supply system shown in FIG. 2;

Embodiments of the subject matter described herein relate to power supply systems and methods for supplying current to a vehicle from a remote location to power the vehicle. The system and method can be used to power the electric motor of the vehicle to propel the vehicle.

A suitable vehicle, in one embodiment, may be a mining vehicle, such as a tow truck. However, not all embodiments of the inventive subject matter described herein are limited to powering mining vehicles. For example, a vehicle as described herein may represent a vehicle for transportation, such as a trolley vehicle, an electric bus, an electric automobile, and the like. At least one embodiment of the inventive subject matter described herein may be used in connection with providing power to powered systems other than vehicles.

FIG. 1 shows an example of a power supply system (100). Due to the one or more off-vehicle, stationary roadside transformers and/or rectifiers, the power supply system is less than one or more embodiments of the other power supply systems described herein. may not be desirable. As shown, the power supply system includes a generator step-up transformer (104), one or more conductive transmission lines (106) (e.g., cables, wires, etc.), one or more step-down transformers (108), and one or more A customer station (110) is conductively coupled to a power plant (102).

In the embodiment shown, the power plant is a power plant producing AC at voltages above 4 kV. In other embodiments, the voltage ranges from less than about 6 kV, from about 6 kV to about 6.5 kV, from about 6.6 kV to about 10 kV, from about 10 kV to about 20 kV, from about 21 kV to about 22 kV. can be In various embodiments, suitable AC voltages may be selected from 11 kV, 13 kV, and 7.200 kV. In other embodiments, the voltage can be relatively small, such as 4.160 kV, 7.200 kV. Voltages are selected with reference to application-specific parameters and are not interchangeable in all applications.

This generated AC may be conducted to a generating step-up transformer, where the voltage of the generated AC is increased. In one embodiment, the voltage may be increased to 100 kV or higher (eg, 138 kV to 765 kV). This high voltage AC may be directed to one or more of the step-down transformers via one or more of the transmission lines. A step-down transformer may step down the voltage of the AC. In one embodiment, this step-down reduces the voltage to a voltage in the range of approximately 4 kV to 14 kV. The stepped-down AC may be directed to the customer station. A suitable customer station may be an electrical substation dedicated to supplying AC to a mine, for example to power vehicles traveling within the mine. The customer station then directs the stepped-down AC to one or more conductive transmission lines (112) of the power supply system within the mine.

The AC that is led into the mine's power lines may be of relatively high voltage. The frequency of the AC directed into the mine's transmission line may be controlled or limited to the frequency of the AC directed from outside the mine. In one example, the frequency of the AC directed from the customer station to the transmission line is between 50 Hz and 60 Hz, as the frequency of the AC directed from the power plant over the transmission line to the customer station may be at a frequency of 50 Hz or 60 Hz. may be one of

Within the mine, the power supply system may include one or more stationary, off-board, roadside transformers (114) that receive stepped-down AC from customer stations. Stationary, external, roadside transformers further step down (e.g., step down) the voltage of the AC conducted along the transmission lines of the power supply system. The power supply system may include one or more stationary, off-vehicle roadside rectifiers (116). These rectifiers may convert AC with stepped-down voltage to DC. A suitable stepped-down voltage may range from about 1.8 kV to 2.4 kV DC. Although only a single transformer and a single rectifier are shown in FIG. 1, several transformers and rectifiers may be provided, especially if the transmission line is long. For example, transformers and rectifiers may be spaced from each other at regular, recurring separation distances along the transmission line.

Each transmission line may need to have a relatively large diameter (eg, low gauge) due to the peak voltage and frequency of the AC current conducted through the transmission line. In one embodiment, a suitable transmission line may be a double (parallel) 150 mm ² copper wire. Some systems have additional aluminum or copper feed cables that do not directly contact the vehicle's pantograph, but run along the pole to reduce losses due to dry drop in effective resistance. may have An exemplary infrastructure system may have two 150 mm ² copper wires and three 454 mm ² aluminum wires running parallel over the poles and jumper wires. Smaller (eg, larger gauge) transmission lines may not be able to conduct AC with this large peak voltage and/or this high frequency throughout mines and other areas.

This stepped-down DC may be directed along power lines within the mine to pantographs or other current collectors (118) on vehicles (120) within the mine. (A current collector is a pantograph, sliding shoe, or other device on the vehicle that conducts power between a stationary external source and the vehicle when the vehicle is in motion. .) Although only a single vehicle is shown, several vehicles can also receive DC from the rectifier over the transmission line at the same time. These vehicles may be mining vehicles or other vehicles having a propulsion system (eg, an electric traction motor (122)) in conductive communication with the vehicle's pantograph. The vehicle may have auxiliary loads in addition to the propulsion system. Suitable auxiliary loads may include power tools, heating and cooling, power take-off devices, communication systems, and the like. The traction motor may be powered by DC received from the transmission line of the power supply system to propel the vehicle. A suitable vehicle may have a battery pack that can be charged from the pantograph. The traction motor may be powered directly from the power line (via power electronics), indirectly from the battery pack, or selectively from either or both the battery pack and the power line. good. In one embodiment, another source of electricity may be present for propulsion and/or auxiliary loads. A suitable additional electrical source may include a fuel cell.

a number of stationary off-vehicle roadside transformers and a number of stationary off-vehicle roadside rectifiers are stationary off-vehicle roadside transformers and/or This may increase the cost and complexity of the power supply system compared to some stationary, roadside power supply systems outside the vehicle that do not include rectifiers.

FIG. 2 shows another example of a power supply system (200). The power supply system differs from the power supply system shown in Figure 1 in several ways. As an example, the power supply system does not include some off-board stationary roadside transformers or some off-board stationary rectifiers. The system may include one or more transmission lines (212). A suitable transmission line may include a conductive path. Suitable electrically conductive pathways may include one or more of catenary overhead wires, cables, wires, third rails, and the like. The power supply system may include at least one mobile transformer (214) on the vehicle and/or at least one mobile rectifier (216) on the vehicle. Transformers and/or rectifiers are electrical in that the transformers and/or rectifiers may be coupled to and/or supported by the vehicle and may move with the vehicle as it moves. It may be mounted on a vehicle (220). Suitable vehicles may include trolleys, agricultural equipment, mining equipment, passenger cars, industrial equipment, and the like.

In the illustrated embodiment, the vehicle includes both an on-board transformer and an on-board rectifier. However, as described below, the vehicle may not include an on-board transformer. The power supply system may be located entirely within the outer boundary of an above-ground mine or an underground mine. In various embodiments, one or more power lines may extend above, along, or below a path along which vehicles may travel within the mine. Alternatively, the power supply system may be located partially or completely outside the mine. The power supply system may power the vehicle's traction motors via an on-board transformer and/or an on-board rectifier to propel the vehicle through the mine.

The electric load tractor that travels the mine may be powered via overhead catenary lines and pantographs on the track, although not all embodiments are limited to this arrangement. The transmission line may be an electric rail that supplies power to rail cars, trolleys, and the like. A vehicle may be a rail car (carrying passengers or other cargo), a trolley, or the like.

The vehicle controller (224) is one or more (eg, one or more microprocessors, integrated circuits, field programmable gate arrays, etc.) that controls the operation of the vehicle as described herein. and/or hardware circuitry coupled to one or more processors. The controller generates a control signal and sends the control signal to an on-board rectifier switch (described herein) so that AC derived from the transmission line is supplied by the on-board rectifier to power the traction motor. The operation of the on-board rectifier can be controlled by controlling whether or not it is converted to direct current for supply. The controller may receive to control vehicle movements, such as changing throttle settings (eg, by changing the position of levers, pedals, etc.). This input can be provided by the driver of the vehicle, by a controller or other system that automatically controls the movement of the vehicle, from an off-board transmission system, by an off-board operator, and the like. A suitable controller includes wireless transmit and receive hardware (e.g., antennas, modems, etc.) for receiving control signals from a remote location (e.g., a driver located outside the vehicle) to remotely control operation of the vehicle. May contain.

In operation, polyphase AC may be led from the power plant to the transmission lines of the power supply system. The transmission lines shown in plan view in FIG. 2 represent a plurality of transmission lines, each conducting a different phase of AC from the power plant to the vehicle. For example, there may be three transmission lines, each carrying a different phase of three-phase alternating current from the power plant. Alternatively, 2-phase, 4-phase, etc. AC may be led from the power plant to the vehicle via the same number of transmission lines.

This AC may be received directly by the vehicle from the power line. For example, instead of a vehicle receiving DC current from a power line like the vehicle in the example of FIG. 1, the vehicle may receive AC from the power line. This AC is not rectified by any off-board rectifier, but is routed as AC to the vehicle's on-board transformer. A vehicle's on-board transformer can step down (eg, step down) the AC voltage. For example, a power plant may output AC on, through, or via transmission lines that have peak voltages. In other embodiments, the voltage may be controlled to be between the positive (or upper) and negative (lower) peaks of the AC waveform. When using peak voltage, a suitable peak voltage may be at least 4 kV in one embodiment. In another embodiment, the peak voltage can be at least 10 kV. In another embodiment, the peak voltage can be at least 11 kV. In still other embodiments, the peak voltage can be at least 13 kV. In some embodiments, the voltage may be selected such that the peak voltage is below the voltage that could cause a failure or overheat condition in the transmission line. Optionally, the peak voltage can range from about 4 kV to about 25 kV. The selection of peak voltage may be made with reference to application specific parameters. These parameters may include one or more of current, wire gauge, end use application, load duration, load ramp rate, environmental factors, electrical supply factors, and the like.

Loss of vehicle connection to the neutral line (of the power supply system) can pose a safety hazard to the driver due to increased voltage, and disconnection of the vehicle from the neutral line reduces the vehicle's reference voltage to , undesired voltages, or may fluctuate to relatively high voltages. For example, the body and/or chassis of a vehicle may be at high potentials or voltages due to voltages provided over power lines. In one embodiment, the vehicle may contact and/or receive voltage via the power line only while the vehicle is in motion. The system can be configured such that the driver (by rule, regulation, or ability to reach the vehicle) cannot touch the vehicle in motion.

In one embodiment, the transformer that supplies current to the transmission line may include a center tap. This center tap may reduce vehicle excursions (eg, vehicle body or chassis voltage or potential when disconnected from the neutral line) compared to the absence of the center tap. For example, a center tap may cut or lower the maximum voltage or potential of a vehicle body or chassis by half (compared to a transformer that does not include a center tap).

Additionally or alternatively, the vehicle has a switch (e.g., contactor, circuit breaker, etc.) that disconnects the vehicle by creating an open circuit to it when it detects that the vehicle is no longer connected to the neutral line. may contain For example, a vehicle may have multiple (eg, two) current collectors that are attached to power lines. Each of these current collectors may receive single phase AC from a different transmission line. If the voltage from one single-phase AC to a reference (e.g. ground ground for vehicle chassis or power supply system) does not exceed a specified threshold within a specified period of time. A suitable specified threshold may be 40V or another value. In one example, the specified period may be 1/f, where f is the fundamental power frequency of the AC. The reference voltage may be measured as an amplitude (eg, peak positive or peak negative AC voltage), the root mean square value of the AC voltage, or a direct reading of the AC voltage. A switch may generate an open circuit in response to a measured voltage exceeding a threshold within a specified period of time.

Additionally or alternatively, the controller determines that the maximum voltage allowed to be conducted through the power line is that the vehicle's tires are insulated and conducted to ground (one of the power conductors is shorted to the vehicle's ground reference). The system can be operated so that it can be limited to a value that can prevent ground fault events). The smallest tire size for the vehicle may be used to calculate the maximum voltage allowed to be drawn from the power line to the vehicle. For example, the smallest tire on a vehicle that can be connected to a power line is a 60 inch radius, but with a 57 inch diameter conductive rim and a 31.5 inch path between the chassis and the ground ground reference. You may have The standard voltage creep of the environment in which the vehicle operates (e.g., the distance that various voltages can jump or be transferred between) may be 3 inches per 2 kV, and the air gap or void The gap voltage jump may be approximately 1 inch per 2 kV. The system can assume conservative limits such that there is a 30 inch linear distance or profile between the vehicle's conductive parts (eg, rims) and the surface on which the vehicle's tires are running. Using standard voltage creep and air gaps, the system may calculate and indicate that the line voltage can be limited to 20 kV. This limit can prevent or reduce the potential for body or chassis voltages to jump to surfaces in the event of a ground fault, thereby reducing the chances of the vehicle's tires or nearby components being ignited (e.g. by arcing). to reduce or eliminate the possibility of injury.

The AC may be line-routed from the power plant at a frequency based at least in part on the utility power line frequency. For example, AC may be derived from a power plant at a frequency such as 50-60 Hz that is directed onto the power grid for consumer use. Alternatively, the frequency of the AC directed from the power plant to, through, or via the transmission line may be less than 50 Hz. Alternatively, the frequency of the AC conducted from the power plant to, through, or via the transmission line may be above 60 Hz and below 1 kHz. Alternatively, the frequency of the AC conducted from the power plant to, through, or via the transmission line may be at least 1 kHz and no more than 5 kHz. Alternatively, the frequency of the AC conducted from the power plant to, through, or via the transmission line may be at least 5 kHz and no more than 6 kHz. Alternatively, the frequency of the AC directed from the power plant to, through, or through the transmission line may be low frequency, such as less than 50 Hz.

The on-board transformer may receive multi-phase AC from the transmission line and step down the voltage of the multi-phase AC. For example, an on-board transformer is a delta-wye transformer having a delta-connected winding on the transformer's primary winding and a wye or star-connected winding on the transformer's secondary winding. It can be. Alternatively, the transformer may be another type of transformer. The transformer may reduce the peak voltage of the polyphase AC and supply the reduced voltage polyphase AC to the on-board rectifier. For example, in various embodiments, the transformer reduces the peak voltage of polyphase AC from at least 4 kV, at least 10 kV, at least 11 kV, or at least 13 kV to 1.8 kV, 2.4 kV, or 1.8 kV and 2.4 kV. You can lower it between A reduced voltage polyphase AC may be routed from an on-board transformer to an on-board rectifier.

An on-board rectifier may then convert the polyphase AC to DC and feed a variable frequency drive (VFD) (226). A VFD may include one or more inverters that convert DC received from an on-board rectifier to AC. A VFD uses one or more inverters to control the frequency of the AC in order to control the speed at which the motor runs. For example, the controller may direct the VFD to generate AC at different frequencies depending on the desired speed or torque output of the traction motor. The controller may direct the VFD to generate AC at a higher frequency in order to increase the rotational speed and/or torque output by the traction motor. By powering the VFD with DC from the on-board rectifier, the vehicle can operate at different speeds and/or different torque outputs at different times.

Placing transformers and rectifiers on the vehicle may reduce the cost and complexity of the power supply system. For example, since the transformers and rectifiers move with the vehicle, the need to install several off-vehicle, stationary transformers and rectifiers at multiple locations along the transmission line is reduced or eliminated. Maybe. The voltage received by the transformer and rectifier on the vehicle may drop by the ratio of the turns of the transformer (e.g. the turns of the coil in the transformer), and thus the current increases by the ratio of the turns of the transformer. Catenary contacts and feeder wires may need to be classified according to their current rating. Therefore, if the voltage remains at 10 kV to transmit 5 MW of power, the overhead line may be rated at 500 amperes (RMS). If the voltage is reduced to 1400-2600V (DC) of conventional DC catenary to transmit 5 megawatts, the catenary may need to be classified from 3500 amps to 1900 amps respectively.

In another embodiment, single-phase AC is directed from the power plant to a single transmission line or to each of multiple transmission lines of the power supply system. This single-phase AC may be received directly by the vehicle's pantograph from the power line. This single-phase AC is not rectified by any off-board rectifiers and is led as single-phase AC to the vehicle's on-board transformer. A vehicle's on-board transformer can step down (eg, reduce) the voltage of single-phase AC. For example, a transmission line may conduct single-phase AC from a power plant with a peak voltage of at least 4 kV. In other embodiments, the peak may range from at least about 10 kV to about 13 kV. Depending on the end-use application, the peak value may be chosen to be a voltage lower than the voltage at which the transmission line would fail or overheat. AC current may be conducted at low frequency from the power plant in the transmission line. Suitable low frequencies may be in the range of about 50 Hz, about 60 Hz, and so on.

The onboard transformer may receive single phase AC from the transmission line and step down the voltage of the single phase AC. The transformer can supply reduced voltage, single-phase AC to the on-board rectifier. For example, a transformer can reduce the peak voltage of single-phase AC from at least 4 kV. In other embodiments, the reduction is from at least 10 kV, or at least 11 kV. In other embodiments, the reduction may be from at least 13 kV to about 1.8 kV. A reduced voltage single-phase AC may be led from the on-board transformer to the on-board rectifier. An on-board rectifier may then convert the single-phase AC to DC that is supplied to the VFD. The VFD may generate AC with a frequency controlled by the controller to drive the traction motors.

In one embodiment, the power supply system may include an energy storage device (234). A suitable energy storage device may have one or more rechargeable batteries capable of receiving at least a portion of the DC output by the on-board rectifier. An energy storage device may store electrical energy from the DC bus. This DC current is used to power one or more auxiliary devices (e.g., devices that do not operate to propel the vehicle) and/or to power a motor via the VFD. can be Alternatively, the energy storage device may include one or more fuel cells, capacitors (eg, super-capacitors or ultra-capacitors), flywheels, compressed air containers, electrolyzers, and the like.

AC conducted through or via transmission lines may have frequencies different from those listed above. For example, instead of a low frequency of 50-60 Hz, the AC directed into the transmission line by a power plant may have a frequency of at least 4 kHz. In other embodiments, the AC frequency may be at least 5 kHz. In other embodiments, the AC frequency may be at least 6 kHz. Optionally, the AC frequency may be in the range of approximately 1 kHz to 10 kHz. While higher frequency AC routed through power lines can afford room for size and weight of on-board transformers compared to lower frequency AC routed through power lines, , receives the same (or greater) power density from the transmission line. For example, an AC frequency of 5 kHz can increase the power density of the AC received by the on-board transformer compared to lower frequencies. Using a smaller, lighter transformer can reduce the weight and size of the vehicle in which the on-board transformer is installed. This allows the vehicle to tow a greater amount of cargo compared to vehicles with larger and/or heavier on-board transformers.

In one embodiment, the on-board rectifier is controlled (by the on-board rectifier and/or controller) to convert the stepped-down AC received from the on-board transformer to DC for powering the motor. , including switches. These switches can be semiconductor switches, such as doped silicon semiconductor switches. Alternatively, the switches may be semiconductor switches with higher performance than doped silicon semiconductor switches. For example, switches in a rectifier operate to control AC conduction through the rectifier with less loss than doped silicon switches such as silicon carbide (SiC) switches, gallium nitride (GaN) switches, and the like. Also good. FIG. 10 shows an example of an on-board rectifier. As shown, the on-board rectifier receives power from the on-board transformer (eg, via the "AC side" in FIG. 10) to power the motor (eg, via the "motor side" in FIG. 10). It may include a switch (1002) controlled (by the onboard rectifier and/or by the controller) to convert the received stepped down AC to DC. Suitable switches may be semiconductor switches. Suitable semiconductor switches can include doped silicon semiconductor switches, gallium nitride semiconductor switches, and silicon carbide semiconductor switches. Suitable rectifiers can receive 3-phase AC (as shown by the 3 AC side inputs in FIG. 10), or are selected to receive 6-, 12-, 18-, or 24-phase AC. obtain. The selection can be made based on application-specific parameters.

FIG. 3 shows another example of a power supply system (300). The power supply system (300) differs from that shown in Figure 2 in that the vehicle does not include an on-board transformer between the power line and the on-board rectifier. Alternatively, one or more stationary, off-board, roadside transformers (314) may be coupled to or located along the power line. Roadside transformers can step down the peak voltage of AC conducted along or through transmission lines, after which the AC is received by an on-board rectifier via a pantograph. The on-board rectifier then converts the stepped-down AC to DC current that is provided to the VFD for powering and controlling the vehicle motor, as described above. can be done. Since the vehicle continues to have a VFD, the vehicle can move at different speeds as the VFD changes the frequency of the AC output by the VFD to the motor. Removing the on-board transformer (shown in FIG. 2) from the vehicle and using an off-board transformer (314) may increase the cost of the power supply system, but reduce the weight borne by the vehicle. can be done. This may allow the vehicle to carry a greater load or cargo compared to one or more of the vehicles equipped with on-board transformers.

FIG. 4 shows another example of a power supply system (400). This power supply system may include the on-board transformer described above, but does not include the on-board rectifier described above. Instead, the power supply system includes one or more switches (430) positioned between the vehicle's pantograph and the on-board transformer. Suitable switches may include, for example, electromechanical contactors or relays, and/or may include power transistors or other solid state switching devices. In the drawings, the switches are shown as contactors, by way of example. In one embodiment, the switch includes one or more three-phase contactors.

The switch is operable to make or break a conductive connection between the pantograph and the on-board transformer. The switch can be controlled open or closed by a controller. When the switch is open, AC drawn from the power station via the transmission line may not be drawn through the pantograph to the on-board transformer. As a result, the motor may not be powered and may not use AC from the power line to propel the vehicle. When the switch is closed, AC drawn from the power plant via the transmission line is conducted through the pantograph to the on-board transformer.

An on-board transformer may step down the peak voltage of the AC received from the transmission line, which is then directed to the vehicle's traction motors. The stepped-down AC from the on-board transformer may be directed to the traction motor via one or more conductive paths (428) (eg, cables, wires, buses, etc.) on the vehicle. The traction motor is electrically powered by the stepped-down AC to propel the vehicle. Since the frequency of the AC routed on the transmission line and stepped down by the on-board transformer is not changed, the traction motor may be limited to operating at a single speed corresponding to this frequency. For example, the traction motor may rotate the vehicle's wheels at a fixed or unvarying speed because the AC frequency does not change.

As shown in Figure 4, the power supply system may not include a rectifier (either on-board or off-board) between the power plant and the vehicle. For example, no rectifier may change AC (or any portion of AC) to DC between the power plant and the vehicle's motor.

FIG. 5 shows another example of a power supply system (500). This power supply system differs from other power supply systems in that the power supply system does not include any on-board transformers or on-board rectifiers. Additionally, the power supply system may include one or more off-board transformers that reduce or step down the peak voltage of the AC provided by the power station. An off-board transformer may reduce the peak voltage to a level that can be used to power the vehicle's traction motors directly. The stepped-down AC may be directed to the vehicle via power lines and pantographs. The controller can control the conduction of stepped-down AC from the power lines and pantographs to the motor using contactors or other switches, as described above.

The stepped-down AC received from the power line may be directed to the traction motor via conductive paths on the vehicle. The traction motor can then be electrically powered by the stepped-down AC to propel the vehicle. Since the frequency of the AC routed on the transmission line and stepped down by the on-board transformer is not changed, the traction motor may be limited to operating at a single speed corresponding to this frequency. For example, the traction motor may rotate the vehicle's wheels at a fixed or unvarying speed because the AC frequency does not change. In one embodiment, the power supply system may not include any rectifiers (on-board or off-board) between the power plant and the vehicle. For example, no rectifier may change AC (or any portion of AC) to DC between the power plant and the vehicle's motor.

FIG. 6 shows a flowchart of one embodiment of a method (600) for powering a motor of a vehicle for powering a motor. A method describes the operation of one or more power delivery systems described herein. For example, the method describes operation of the power supply system shown in FIG. At step 602, AC is received at a transformer on the vehicle, from one or more transmission lines, and via one or more conductive bodies, such as one or more pantographs. Optionally, a brush, conductive shoe, or other conductive body can be used. At step (604), the AC peak voltage is stepped down by the on-board transformer. At step (606), the stepped-down AC is also received at a rectifier located on the vehicle. At step (608), the on-board rectifier converts the stepped-down AC to DC. At step (610), the DC output by the rectifier is received at the variable frequency drive. At step (612), the variable frequency drive generates a variable frequency current (eg, AC having a frequency that can be varied under control by the variable frequency current). At step 614, this variable frequency current is supplied to one or more electric traction motors (eg, motors) of the vehicle to power the motors and control the speed of the motors. The speed of the motor can be controlled by varying the frequency of the variable frequency current.

FIG. 7 shows a flowchart of one embodiment of another method (700) for powering a motor of a vehicle for powering a motor. A method describes the operation of one or more power delivery systems described herein. For example, the method describes operation of the power supply system shown in FIG. At step (702), AC is received at a transformer located outside the vehicle. An off-board transformer can receive AC from one or more transmission lines. At step (704), the AC peak voltage is stepped down by an off-board transformer. This stepped-down AC can be rerouted to the power line and directed towards one or more vehicles. At step (706), the stepped-down AC is also received at a rectifier located on the vehicle. The stepped-down AC may be received by a rectifier through one or more of the vehicle's conductive bodies, such as pantographs, brushes, conductive shoes, and the like. At step (708), the on-board rectifier converts the stepped-down AC to DC. At step (710), the DC output by the rectifier is received at the variable frequency drive. At step (712), the variable frequency drive produces a variable frequency current (eg, AC having a frequency that can be varied under control by the variable frequency current). At step 714, this variable frequency current is supplied to one or more electric traction motors (eg, motors) of the vehicle to power the motors and control their speed. The speed of the motor can be controlled by varying the frequency of the variable frequency current.

FIG. 8 shows a flowchart of one embodiment of another method (800) for powering a motor of a vehicle for powering a motor. A method describes the operation of one or more power delivery systems described herein. For example, the method describes operation of the power supply system shown in FIG. At step (802), AC is received at a transformer on the vehicle from one or more transmission lines. AC may be received via one or more conductive bodies of the vehicle, such as pantographs, conductive shoes, brushes, and the like. At step (804), the AC peak voltage is stepped down by the on-board transformer. The peak voltage can be stepped down without changing the frequency of the AC. At step (806), the stepped-down AC may be directed from the on-board transformer to the vehicle's motor. For example, the stepped-down AC can be directed to the vehicle's electric motor without changing the frequency of the AC or converting the AC to DC. A fixed frequency AC, as described above, is directed to the motor and powers the motor to operate it at a single speed.

FIG. 9 shows a flowchart of one embodiment of another method (900) for powering a motor of a vehicle for powering a motor. A method describes the operation of one or more power delivery systems described herein. For example, the method describes operation of the power supply system shown in FIG. At step (902), AC is received at a transformer external to the vehicle from one or more transmission lines. At step (904), the AC peak voltage is stepped down by an off-board transformer. The peak voltage can be stepped down without changing the frequency of the AC. The stepped-down AC can be reconnected to the transmission line and directed towards the vehicle. At step 906, fixed frequency step-down AC may be received from the power line by the vehicle. For example, AC may be received via one or more conductive bodies of the vehicle, such as pantographs, conductive shoes, brushes, and the like. At step (908), the AC is directed to the vehicle's motor. For example, stepped-down, fixed frequency AC can be directed to the vehicle's electric motor without changing the frequency of the AC or converting the AC to DC. A fixed frequency AC, as described above, is directed to the motor and powers the motor to operate it at a single speed.

FIG. 11 shows another example of a power supply system similar to that shown in FIG. The power supply system may include a roadside step-down transformer outside the vehicle, which receives AC from the power plant. This transformer can receive 13 kV 3-phase AC from the power plant and step down this AC to 480 V 3-phase AC (with a frequency of 60 Hz). Alternatively, the current can be stepped down to another voltage. This stepped-down AC can be split and directed to a DC-AC converter via cables or other conductors. Suitable converters may be inverters and switches that convert AC received from roadside transformers to high voltage (eg, 12-25 kV), single-phase AC. Transformers along the road can step down the voltage so that a switch can convert the AC to a higher voltage. This single-phase AC may be led to an off-board transformer outside the vehicle, which includes or is connected to a center tap.

In the embodiment shown, each of the two transmission lines conducts single-phase AC that is supplied to the vehicle via current collectors. The phase of AC conducted in transmission lines may vary. For example, line-guided AC may have a phase difference of 180 degrees. In another embodiment, the AC may be 180 degrees out of phase. In another embodiment, the line-guided AC may have a phase difference other than 180 degrees. The appropriate phase difference may be selected based on application specific parameters and between transmission lines, may affect the magnitude of the voltage delivered to the vehicle via the current collector, or may may control the For example, a 180 degree phase difference between AC may provide a large voltage to the vehicle, while a 90 degree phase difference may provide half this maximum voltage to the vehicle, with no phase difference. In some cases, it may provide no voltage to the vehicle, or only a minimum voltage, and so on.

The vehicle's on-board transformer may receive AC from the transmission line through a current collector. This transformer can step down the voltage. In one example, this step-down may be from about 25 kV AC to about 2.660 kV AC, or may be selected from other values based at least in part on the application. The voltage can be stepped down and led to the on-board rectifier. In the example shown, the on-board transformer includes three coils that separately direct single-phase AC to three AC-DC rectifiers as on-board rectifiers. Each of these rectifiers may include a 1.7 kV silicon carbide diode rectifier that converts AC to DC. This DC is output by a rectifier to a converter on the vehicle. The converter may be a DC-DC converter that changes the DC voltage received from the rectifier. For example, the converter can reduce the DC voltage received from the rectifier to a reduced voltage that can be used to charge an energy storage device coupled with the converter, as shown in FIG.

The converter may be connected to a plurality of DC-DC converters, each DC-DC converter varying the voltage output by it. Each of these converters may be connected to a different inductor (1110), which may be coupled to another energy storage device. In one embodiment, the vehicle has either an energy storage device coupled to the converter or an energy storage device coupled to the inductor. Alternatively, the vehicle may have both an energy storage device coupled to the converter and an energy storage device coupled to the inductor.

The inductor and/or energy storage device is coupled to another converter (1112) comprising one or more legs with resistors (1114), capacitors (1116), ground connections (1118), etc. connecting the converter in parallel. It's okay to be there. The converter changes the voltage output by the inductor and/or the energy storage device and then supplies this voltage to the vehicle's traction motor. A motor is powered by this voltage to propel the vehicle. In one embodiment, one or more of the energy storage devices provide electrical energy (eg, DC) to the motor to power the motor. A vehicle may include an engine that operates in conjunction with a generator or alternator on the vehicle, thereby producing additional current to power the motor. Alternatively, the vehicle may not include any engine.

While the above description focused on the supply of current from outside the vehicle onto the vehicle (to power the motor and/or charge the energy storage device), it is shown in FIG. The component may direct the current output by the motor back to the energy storage device (to charge the energy storage device) and/or back to the power grid (eg a power plant which may be part of the power grid). can lead to For example, during regenerative braking, the motor produces DC, which may be directed to a converter (where the voltage of the DC can be varied) and then optionally between the converter and the inductor. to energy storage devices, through conductors to other energy storage devices (for charging), and/or to converters (to change the voltage of DC), to rectifiers (to be converted to AC), To the on-board transformer (to step up the voltage), through the current collector to the off-board transformer (to step down the voltage), to the inverter (to convert AC to DC), and then to the transformer You may be led to the power plant through the vessel.

In one embodiment, the power supply system includes an on-board rectifier configured to be located on-board an electric vehicle. The on-board rectifier is configured to receive alternating current directed from the power plant over the transmission line at a frequency that is at least the utility line frequency. The on-board rectifier is configured to convert alternating current to direct current and output the direct current to an electric propulsion system of the electric vehicle to power the propulsion system to propel the electric vehicle. Optionally, the onboard rectifier is configured to receive alternating current at a utility power line frequency that is at least 50 Hertz and no greater than 60 Hertz. Optionally, the onboard rectifier is configured to receive alternating current at a frequency of at least 5 kilohertz, such as at least 6 kilohertz. Optionally, the on-board rectifier is configured to receive alternating current with a peak voltage of at least 10 kilovolts. Optionally, the system also includes an onboard transformer mounted on the electric vehicle and configured to reduce the peak voltage of the alternating current. The on-board transformer can be configured to receive alternating current from the transmission line and to output alternating current with reduced peak voltage at the on-board rectifier.

Optionally, the onboard rectifier includes one or more silicon carbide switches. Optionally, the on-board rectifier is configured to receive alternating current from the power plant, the alternating current not being rectified by the off-board rectifier between the power plant and the electric vehicle. Optionally, the onboard rectifier is configured to receive alternating current as single phase current. Optionally, the on-board rectifier is configured to receive alternating current as multiphase current. Optionally, the system also includes a variable frequency drive configured to receive the direct current output by the on-board rectifier and output a variable frequency current to the electric propulsion system of the electric vehicle. Optionally, the electric vehicle is a mining vehicle or a mobile vehicle.

Optionally, the system also includes an energy storage device configured to be located on-board the electric vehicle and configured to store at least a portion of the direct current output by the on-board rectifier. In one embodiment, a method is provided that includes receiving alternating current at an on-board rectifier located on-board an electric vehicle. Alternating current is received by the on-board rectifier from the power plant over the transmission line and at a frequency that is at least the utility line frequency. The method also includes the steps of converting the alternating current to direct current using the on-board rectifier and supplying the direct current from the on-board rectifier to an electrical propulsion system of the electric vehicle, thereby powering the propulsion system. and propelling the electric vehicle. Optionally, alternating current is received at a commercial power line frequency that is at least 50 Hertz and no greater than 60 Hertz. Optionally, alternating current is received at a frequency of at least 5 kilohertz.

Optionally, alternating current is received at a peak voltage of at least 10 kilovolts . Optionally, the method also includes the steps of receiving alternating current from the transmission line with an on-board transformer and reducing a peak voltage of the alternating current using the on-board transformer, followed by reducing the reduced peak voltage. directing the alternating current to an on-board rectifier. Optionally, alternating current is received from said power plant by an on-board rectifier and alternating current is not rectified between the power plant and the electric vehicle by an off-board rectifier. In one embodiment, the method comprises receiving alternating current at a frequency of at least 50 Hz on an electric vehicle from a power plant via one or more transmission lines; rectifying the alternating current to direct current on the electric vehicle; powering a propulsion system of an electric vehicle, using direct current to power the propulsion system and propel the electric vehicle.

Optionally, alternating current is received at a frequency of at least 5 kilohertz. Optionally, alternating current is received at a peak voltage of at least 10 kilovolts . Optionally, alternating current is received from a power plant, but the alternating current is not rectified off-board the electric vehicle. Optionally, the alternating current is received as single phase current. Optionally, alternating current is received as polyphase current.

In one embodiment, a method is provided comprising the steps of directing alternating current from a power plant at utility power line frequency through one or more transmission lines, and receiving the alternating current at a rectifier on a vehicle, wherein the alternating current is non-rectified off-board between the power plant and the vehicle; rectifying alternating current on-board the vehicle to thereby generate direct current; and one or more electric traction motors of the vehicle using direct current. and providing power to the.

In one embodiment, the power supply system includes an on-board rectifier configured to be located on-board an electric vehicle. The on-board rectifier is configured to receive alternating current directed from the power plant over the transmission line at a frequency of 50 Hertz to 60 Hertz, or at a frequency of 50 Hertz or greater (eg, 60 Hertz or greater). The on-board rectifier is configured to convert alternating current to direct current and output the direct current to an electric propulsion system of the electric vehicle to power the propulsion system to propel the electric vehicle.

In one embodiment, an electric vehicle includes a chassis, a power supply system, and an electric propulsion system. One or more electric motors operably connected to one or more wheels, trucks, propellers, or the like. A power supply system and an electric propulsion system are mounted on the vehicle and are connected to and supported by the chassis. The power supply system includes an on-board rectifier, an on-board transformer, and a current collector. A current collector is electrically connected to the transformer and configured to contact the power line during movement of the vehicle to conduct electricity from the power line to the transformer. The output of the transformer is electrically connected to the rectifier. A rectifier may receive an alternating current derived from a power plant via transmission lines, current collectors, and transformers at frequencies that are greater than or equal to 50 Hertz. The rectifier changes the alternating current to direct current and outputs the direct current to the electric propulsion system of the electric vehicle to power the propulsion system to propel the electric vehicle. A transformer may reduce the peak voltage of the alternating current.

As used herein, the terms "processor" and "computer" and related terms such as "processing device", "computing device", and "controller" are referred to in the art as computers. It may not only be limited to integrated circuits, but may refer to microcontrollers, microcomputers, programmable logic controllers (PLCs), field programmable gate arrays, and application specific integrated circuits, as well as other programmable circuits. Suitable memory can include, for example, computer readable media. The computer-readable medium can be, for example, a computer-readable non-volatile medium such as random access memory (RAM), flash memory, and the like. The term "non-transitory computer-readable media" is implemented for the short-term and long-term storage of information such as computer-readable instructions, data structures, program modules and sub-modules or other data on any device. Represents a tangible computer-based device that Accordingly, the methods described herein are encoded as executable instructions embodied in tangible, non-transitory computer-readable media including, but not limited to, storage devices and/or memory devices. Also good. Such instructions, when executed by a processor, cause the processor to perform at least a portion of the methods described herein. As such, this term includes tangible computer-readable media including, but not limited to, non-transitory computer storage devices, which include volatile and non-volatile media. , and removable and non-removable media, including but not limited to firmware, physical and virtual storage, CD-ROMs, DVDs, and other media such as networks and the Internet. Including digital sources.

As used herein, the singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise. "Optional" or "optionally" means that the event or circumstance subsequently described may or may not occur and the description may include whether the event does or does not occur do. As used throughout the specification and claims, language denoting approximate numbers is used to modify quantitative expressions that may vary within permissible limits without changing the underlying functionality with which they may be associated. may apply. Thus, the value modified by term(s) such as "about," "substantially," "approximately," may not be limited to the exact value specified. In at least some cases, the language for approximate numbers may correspond to the precision of an instrument for measuring the value. Here and throughout the specification and claims, range limitations may be combined and/or interchanged, and unless the context or language indicates otherwise, such ranges are identified, and All subranges contained therein are included.

This written description uses examples to disclose the embodiments, including the best mode, and to enable one skilled in the art to make and use any device or system, and to implement the methods encompassed. Enables practicing embodiments of the invention. The claims define the patentable scope of the disclosure, and may include other examples that occur to those skilled in the art. Such other examples may be provided that they have structural elements that do not differ from the written language of the claims, or that they have equivalent structural elements that do not differ substantially from the written language of the claims. If an element is included, it is intended to be within the scope of the claims.

Claims (15)

A power supply system, the power supply system comprising:
an on-board rectifier configured to be located on-board a vehicle, the on-board rectifier comprising:
configured to receive alternating current directed at a commercial power line frequency of at least 50 Hertz and no greater than 60 Hertz from a power plant over one or more transmission lines;
The on-board rectifier is configured to change the alternating current to direct current,
the on-board rectifier outputs the direct current to an electric propulsion system of the vehicle to power the electric propulsion system to propel the vehicle ;
an on-board transformer mounted on the vehicle and configured to reduce a peak voltage of the alternating current;
The on-board transformer is configured to output the alternating current having the reduced peak voltage to the on-board rectifier,
A power supply system , wherein the on-board rectifier is configured to receive the alternating current at a peak voltage of at least 10 kilovolts . wherein the electric propulsion system is configured to generate additional direct current from dynamic braking, and the on-board rectifier directs the additional direct current to the one or more power lines remote from the vehicle. 10. The power supply system of claim 1, configured to convert to static alternating current. 2. The power supply system of claim 1, wherein said on-board rectifier comprises one or more silicon carbide switches. the on-board rectifier is configured to receive the alternating current from the power plant;
2. The power supply system of claim 1, wherein the alternating current is not rectified by an off-board rectifier between the power plant and the vehicle. 2. The power supply system of claim 1, wherein the on-board rectifier is configured to receive the alternating current as single phase current. 2. The power supply system of claim 1, wherein the on-board rectifier is configured to receive the alternating current as polyphase current. 2. The power supply of claim 1, further comprising a variable frequency drive configured to receive the direct current output by the on-board rectifier and to output a variable frequency current to the electric propulsion system of the vehicle. system. one or more energy storage devices, further comprising one or more energy storage devices configured to receive the direct current from the on-board rectifier to charge the one or more energy storage devices; The energy storage devices discharge electrical energy stored in the one or more energy storage devices, power one or more motors of the electric propulsion system of the vehicle, and power the electric propulsion system. 2. The power supply system of claim 1, configured to propel the vehicle using a power supply system. configured to control the maximum voltage that can be conducted over the one or more transmission lines, thereby limiting the maximum voltage to a predetermined value based at least in part on the insulation value of the vehicle to ground; 2. The power delivery system of claim 1, further comprising a controller that An electric vehicle comprising the power supply system of claim 1, wherein the electric vehicle is a mining vehicle or a locomotive vehicle. A method, the method comprising:
A step of receiving an alternating current with an on-board rectifier arranged on a vehicle, wherein the alternating current is
received by an on-board rectifier from a power plant over one or more transmission lines and at a frequency that is at least utility power line frequency and a peak voltage of at least 10 kilovolts;
converting the alternating current to direct current using the on-board rectifier; and
supplying the direct current from the on-board rectifier to an electric propulsion system of the vehicle,
thereby powering the electric propulsion system to propel the vehicle;
including
receiving the alternating current from the transmission line with an on-board transformer; and
reducing the peak voltage of the alternating current using the on-board transformer,
thereafter, directing said alternating current having said reduced peak voltage to said on-board rectifier;
The method , wherein the alternating current is received by the on-board rectifier at a utility power line frequency of at least 50 Hertz and less than or equal to 60 Hertz . 12. The method of claim 11 , wherein said alternating current is received at a frequency of at least 5 kilohertz. 12. The method of claim 11, wherein the alternating current is received from the power plant by the on-board rectifier and the alternating current is not rectified between the power plant and the vehicle by an off-board rectifier. A method, the method comprising:
receiving alternating current at a frequency of at least 50 Hertz and no more than 60 Hertz from a power plant on a vehicle via one or more transmission lines;
rectifying the alternating current to direct current on the vehicle ; and
powering a propulsion system using the direct current to power a propulsion system of the vehicle to power the propulsion system to propel the vehicle;
including
The method wherein said alternating current is received on said vehicle at a peak voltage of at least 10 kilovolts . 15. The alternating current is received from a power plant but does not rectify the alternating current off-vehicle .
The method described in .